Atrial natriuretic hormone

Nontraditional Hormones. Novel hormones identified ia cardiovascular tissue have profound effects on maintenance of blood pressure and blood volume ia mammals. Atrial natriuretic hormone (ANH) is a polypeptide hormone secreted from the atria of the heart. When the cardiac atrium is stretched by increased blood volume, secretion of ANH is stimulated ANH ia turn increases salt and water excretion and reduces blood pressure (6). Endothelin is a polypeptide hormone secreted by endothehal cells throughout the vasculature. Although endothelin is released into the circulation, it acts locally in a paracrine fashion to constrict adjacent vascular smooth muscle and increase blood pressure (7). 

L3. Laragh, J. H., Atrial natriuretic hormone, the renin-aldosterone axis, and blood pressure-electrolyte homeostasis. N. Engl. J. Med. 313, 1330-1340 (1985). 

V4. Vermes, I., Beishuizen, A., Hampsink, R. M and Haanen, C., Dissociation of plasma adreno-corticotropin and cortisol levels in critically ill patients Possible role of endothelin and atrial natriuretic hormone. J. Clin. Endocrinol. Metab. 80, 1238-1242 (1995). 

Keck ME, Holsboer F (2001) Hyperactivity of CRH neiu-onal circuits as a target for therapeutic interventions in affective disorders. Peptides 22 835-844 Kellner M, Wiedemann K, Holsboer F (1992) ANF inhibits the CRH-stimulated secretion of ACTH and cortisol in man. Life Sci 50 1835-1842 Kellner M, Herzog L, Yassouridis A, Holsboer F, Wiedemann K (1995) A possible role of atrial natriuretic hormone in pituitary-adrenocortical imresponsiveness in lactate-induced panic disorder. Am J Psychiatry 152 1365-1367 Kennedy JL, Bradwein J, Koszycki D (1999) Investigation of cholecystokinin system genes in panic disorder. Mol Psychiatry 4 284-285... 

StrOhle A, Kellner M, Holsboer F, Wiedemann K (1998) Atrial natriuretic hormone decreases endocrine response to a combined dexamethasone corticotropin-releasing hormone test. Biol Psychiatry 43 371-375... 

While the angiotensins promote release of aldosterone, the atrial natriuretic hormoner aa cc inhibits release. This group of 21- to 33-residue polypeptides, secreted by cells of the atria (auricles) of the heart, also inhibits release of renin and promotes secretion of both Na+ and water. Thus, they antagonize the action of aldosterone, which promotes Na+ retention. However, there is uncertainty as to the significance of these peptides. The following metabolite of y-tocopherol (Fig. 15-24) has been isolated from urine and is proposed as a new endogenous natriuretic factor.dd... 

A major advance based on cloned genes is the production of new medicines previously unavailable or available in only small amounts. Among these are the interferons287 (Chapter 31) and many hormones such as the interleukins produced by lymphocytes448 and the atrial natriuretic hormones (Chapter 23). Another candidate is the al-protease inhibitor (Chapter 12). Perhaps better inhibitors than the natural one can be devised and produced in bacteria.449... 

Atrial natriuretic hormone (peptide) Heart Kidneys Increase Na+ excretion... 

ATRIOPEPTIN-28 (HUMAN) CARPERITIDE HORSE ATRIAL NATRIURETIC PEPTIDE-28 HUMAN ATRIAL NATRIURETIC FACTOR (99-126) a-hmn ATRIAL NATRIURETIC HORMONE HUMAN ATRIAL NATRIURETIC PEPTIDE (1-28) (99-126) HUMAN ATRIOPEPTIN(l-28) HUMAN ATRIOPEPTIN(99-126) (99-126)-hmn PROATRIOPEPTIN SUN-4936 TRIO-PEPTIN (HUMAN a-COMPONENT)... 

Johnson, A., Lermioglu, F., Garg, U. C., Morgan-Boyd, R., and Hassid, A. (1988). A novel biological effect of atrial natriuretic hormone Inhibition of mesangial cell mitogenesis. Biochem. Biophys. Res. Commun. 152, 893-897. 

Natriuretic Peptide Diuretics. Atrial natriuretic peptide (ANP), an endogenous diuretic, natriuretic, and vasodilator, is a peptide hormone primarily synthesized and stored by atrial cardiocytes, and secreted by the atria in response to mechanical stretch of the atria. It was discovered in the cmde extracts of atria in 1981 (51). ANP is also known as anaritide [95896-08-5] atrial natriuretic factor [104595-79-1] (ANF) auriculin ... 

The atrial natriuretic peptide (ANP) belongs to a family of hormones that have structural similarity and some biological actions in common, such as natriuresis and haemoconcentration. It is synthesized and secreted by the cardiac atrium in response to increased atrial pressure. ANP is believed to act physiologically in an opposing manner to AVP... 

Natriuretic peptides are a family of peptide hormones. All of them contain a 17-amino acid long ring that is closed by a disulfide bond between two cysteine residues. ANP (atrial natriuretic peptide) is mainly expressed in the atria of the heart, whereas BNP (B-type natriuretic peptide) is synthesized in the ventricular myocardium. CNP occurs mainly in the endothelium and is thought to have a paracrine function. ANF and BNF lower blood pressure by a direct effect on smooth muscle and on the salt retention in the kidney. Natriuretic peptides bind and activate particulate guanylyl cyclases. 

The heart is located underneath the sternum and between the lungs. In most adults, it weighs between 250 and 350 grams (0.55-0.77 lb). Its major role is to provide oxygen-rich blood to all organs and areas of the body. As a secondary function, the heart secretes atrial natriuretic factor (ANF), a hormone that regulates blood pressure and volume status. The inability of the heart to pump enough blood to maintain normal body requirements is known as heart failure. Refer to Chapter 3 for more information on heart failure. 

Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) are members of a family of so-called natriuretic peptides, synthesized predominantly in the cardiac atrium, ventricle, and vascular endothelial cells, respectively (G13, Y2). ANP is a 28-amino-acid polypeptide hormone released into the circulation in response to atrial stretch (L3). ANP acts (Fig. 8) on the kidney to increase sodium excretion and glomerular filtration rate (GFR), to antagonize renal vasoconstriction, and to inhibit renin secretion (Ml). In the cardiovascular system, ANP antagonizes vasoconstriction and shifts fluid from the intravascular to the interstitial compartment (G14). In the adrenal cortex, ANP is a powerful inhibitor of aldosterone synthesis (E6, N3). At the hypothalamic level, ANP inhibits vasopressin secretion (S3). It has been shown that some of the effects of ANP are mediated via a newly discovered hormone, called adreno-medullin, controlling fluid and electrolyte homeostasis (S8). The diuretic and blood pressure-lowering effect of ANP may be partially due to adrenomedullin (V5). 

Atrial natriuretic peptide is released from myocardial cells in the atria of the heart in response to an increase in atrial filling, or an increase in plasma volume. This hormone inhibits the release of renin. With less angiotensin Il-induced vasoconstriction of the afferent arteriole, RBF, GFR, and urine output increase. The increased loss of water and solutes decreases blood volume toward normal. 

The steroid hormone aldosterone (see p. 55) increases Na reuptake, particularly in the distal tubule, while atrial natriuretic peptide (ANP) originating from the cardiac atrium reduces it. Among other effects, aldosterone induces Na /K" ATPase and various Na" transporters on the luminal side of the cells. 

The endogenous hormone atrial natriuretic peptide (ANP), which acts to increase blood pressure, is, like many other effector peptides, excised from a longer native chain by an endopeptidase enzyme, that is, an agent that cleaves bonds well along the chain of amino acids. A small-molecule endopeptidase inhibitor lowers blood pressure by inhibiting the release of ANP. The inhibitor candoxatril (6-8) is now... 

---